EOQ Calculator with Price Breaks
The textbook economic order quantity ignores the things that decide real orders: vendor price breaks, case packs, minimum orders and shelf life. This calculator includes them and shows what the right order size saves against what you order today.
- Quantity discounts
- Case-pack rounding
- Shelf-life cap
- No sign-up
01Item & demand
02Costs
Buyer time, receiving, AP, delivery fee
Of unit price; 20–30% is typical
03Vendor price breaks
- $
- $
- $
04Real-world limits
Order in whole cases
0 = none
0 = doesn’t expire
For the savings comparison
Order this many
500tins
125 cases of 4 · $25.20 per tin
- Ordering up to the next price break saves more on unit price than it adds in holding cost. The textbook answer would be 179 tins.
- Orders a year
- 4.8
- Every
- 76 days
- Annual total cost
- $62.2K
- Saved vs. today
- $6,611
05Today vs. optimal
| Annual cost | Today · 80 tins | Optimal · 500 tins | Difference |
|---|---|---|---|
| Purchase price | $67,200 | $60,480 | −$6,720 |
| Ordering | $1,350 | $216 | −$1,134 |
| Holding | $269 | $1,512 | +$1,243 |
| Total | $68,819 | $62,208 | −$6,611 |
06Total annual cost by order size
The drops are your vendor’s price breaks. The cheapest point on the curve is the order size to use, as long as it stays below the shelf-life limit of 1,183 tins.
- Optimal
- What you order today
- Price break / shelf-life limit
07Ordering vs. holding cost
Small, frequent orders cost more in ordering; large orders cost more to hold. The textbook EOQ (179 tins) is where the two curves cross, before price breaks and limits.
- Ordering cost
- Holding cost
1 SKU · $6,611 a year
That is one item. Across 1,800 SKUs and a dozen sites, nobody has time to work out the right order size for each, so they don’t.
Bollard sizes every replenishment order from live demand, vendor price breaks, case packs and shelf life, and shows each site’s buyers when a bigger order earns the next price break.
Method
From textbook EOQ to an order size you can use
Annual cost at order size Q is D·p + (D/Q)·S + (Q/2)·i·p: purchase cost, ordering cost and holding cost, where the unit price p depends on the price break Q falls in.
For each price tier the calculator finds the classic EOQ at that tier’s price, moves it into the tier’s quantity range, and rounds to whole case packs. It then applies the vendor minimum and the shelf-life cap (annual demand ÷ 365 × shelf-life days) and picks the cheapest option.
The result also tells you which limit set the answer, so you can see whether a price break or shelf life decided it.
From one site to every site
Order sizes depend on demand, prices and pack sizes, and all three change.
Bollard sizes every replenishment order from live usage at each site and your vendors’ current price breaks, case packs and minimums, and shows buyers when consolidating orders across sites earns a better price.
- Order quantities from live demand per site
- Vendor price breaks and case packs in the catalog
- Cross-site consolidation to reach price breaks
- Shelf-life aware ordering for perishables
Questions
Frequently asked
What is the EOQ formula?+
Economic order quantity = √(2DS / H), where D is annual demand in units, S is the cost of placing one order and H is the annual cost of holding one unit (here, holding cost % × unit price). It is the order size where annual ordering cost and annual holding cost are equal.
How do quantity discounts change the EOQ?+
With price breaks, the cheapest total cost often sits at the minimum quantity of a discount tier rather than at the textbook EOQ. The calculator compares each tier’s best order size, including the purchase price, and picks the lowest total annual cost.
What should I include in the cost per order?+
The cost of the people and systems involved in one order: raising and approving the PO, receiving and checking the delivery, matching and paying the invoice, plus any per-delivery fee from the vendor. For multi-site organisations this is often $30 to $150 per order.
What is a typical holding cost percentage?+
Usually 20 to 30 percent of item value a year. It combines the cost of capital, storage space, insurance, shrinkage and obsolescence or spoilage. Perishable and high-shrink items run higher.
Why does shelf life cap the order quantity?+
Ordering more than you can use before it expires turns a unit-price saving into waste. The cap is annual demand ÷ 365 × shelf life in days, and the calculator will not recommend a quantity above it.
Is my data uploaded?+
No. Everything runs in your browser, and share links keep your inputs in the URL.
Related tools
All tools- Inventory Carrying Cost CalculatorAdd up capital, storage, shrinkage and spoilage to find what holding stock really costs.
- Safety Stock & Reorder Point CalculatorGet reorder points and par levels from usage, lead-time variability and a target service level.
- Cost per Purchase Order CalculatorAdd up the people-time behind each PO, from request to payment, and compare with benchmarks.
- Par Level CalculatorSet par levels for a delivery schedule and see exactly how much to order today, for one item or a whole par sheet.
Free tools
Calculators and document builders for organisations that buy across many sites.
Runs in your browser
I. Spend & Leakage
II. Purchasing Documents
III. Inventory & Stock
IV. Governance & Controls
Free tools, no sign-up. Your figures are processed in your browser and are not uploaded to a server unless you ask us to email you a result. Results are estimates for planning and do not constitute financial, legal or tax advice.